Chicken roasted with olives, lemon and rosemary makes a quick, delicious and allergen-free meal. The photo and recipe are from “Allergy-Free and Easy Cooking” by Cybele Pascal.

It’s not often that cookbook writers can change lives. But you have only to read the introduction to Cybele Pascal’s new cookbook, “Allergy-Free and Easy Cooking” to understand how Pascal has done just that.

The book’s introduction is written by Sarah Boudreau-Romano, a pediatrician specializing in allergies. Three of her four children have severe food allergies — so severe, in fact, that she put her medical career on hold to stay home and care for them, managing their “daily antihistamines, steroid creams and, all too often, epinephrine.”

Being an allergist, the doctor writes, provided her with zero training to be an allergen-free cook. The cookbooks she found were either too complicated for the novice or filled with recipes that “could not ever have been taste-tested.” The result, she said, was many meals that were allergen-free but nearly inedible.

Pascal and her cookbooks (this is her third) have changed all that. Her books contain recipes for foods that taste terrific and are free of the top nine allergens: gluten, dairy, eggs, soy, peanuts, tree nuts, fish, shellfish and sesame. All of them are absolutely doable by the home cook.

Those who have no allergies might not feel compelled to investigate Pascal’s books. But as we increasingly encounter allergy sufferers — be they our children’s friends, a neighbor, co-workers or relatives — it is handy to know some recipes with which to feed them well.

Sometimes the answer to allergen-free cooking is simple: Pork chops and grilled steaks, for example, have none of the top “offending” foods (as long as you don’t slather the meat with butter or sprinkle it with chopped nuts). The roasted chicken dish below is just such a recipe: simple, delicious and allergen-free.

But sometimes you or your allergy-suffering guests are in the mood for something that is traditionally off-limits. Pasta (contains gluten) with pesto (dairy and nuts) is a good example. Pascal’s pesto is the perfect answer.

Roasted chicken with rosemary, kalamata olives and lemon

Yield: 6 servings

3 large bone-in, skin-on split chicken breasts (2½ to 3 pounds), cut in half crosswise (get the butcher to do it for you, or use a cleaver)

Salt and freshly ground pepper

2 tablespoons olive oil

1 tablespoon minced garlic

1 tablespoon minced fresh rosemary

1 lemon, cut into 8 wedges

15 kalamata olives, split and pitted

2 tablespoons white wine

White rice for serving (optional)

Preheat oven to 450 degrees.

Rinse the chicken and pat it dry. Season with salt and pepper.

Heat oil in a large, heavy casserole or Dutch oven over medium-high until oil starts to shimmer, about 2 minutes. Cook chicken, skin side down, 5 to 6 minutes, until crispy and browned. Flip, being careful to keep the skin attached to the breast, and cook 5 minutes more.

Remove pan from the heat. Sprinkle chicken with garlic and rosemary. Add lemon wedges and olives and drizzle with wine. Bake in the center of the oven for 18 minutes, until cooked through. Serve with white rice, spooning sauce over the rice and chicken.

Preheat oven to 425 degrees. Line a 9-by-13-inch baking pan with foil. Scatter the tomatoes in it, drizzle with 1 tablespoon oil, sprinkle with salt and pepper and toss until all the tomatoes are coated. Roast until tomatoes collapse, about 25 minutes (less if they are really tiny).

Meanwhile, bring a large pot of water to a boil and cook pasta according to package instructions.

Make the pesto: Put hemp seeds in a food processor and grind to a fine meal. Add garlic and basil and blend until finely chopped, scraping down the sides of the bowl as necessary. With the motor running, slowly pour in the oil, pureeing until pesto is smooth. Add salt and breadcrumbs and pulse to combine.

Drain pasta and toss with a little oil to coat. Add pesto and toss, then add roasted tomatoes and gently toss one more time. Garnish with basil leaves (if desired) and serve.